Surampudi, 24, works as a strategic program manager for the company's apps business, so it's been easy for him to work remotely these past few months. He expects that he'll continue to do so for the foreseeable future, regardless of any policy changes at Google or in Mountain View, California, where he lives.

That's because Surampudi has Duchenne muscular dystrophy, a genetic condition that causes progressive muscular degeneration. That makes him one of millions of Americans at high risk for complications if he contracts Covid-19.

"I have to be careful and really don't want to put myself in a situation where I could end up in the hospital," he said by phone. "I recognize that it could be a year or longer."

Surampadi is just one of about half a dozen people who told CNBC they're preparing to remain at home until there's a vaccine available, which could take 18 months or more, or until they hear from a scientific expert such as Dr. Anthony Fauci that it's safe for them to resume life as normal.

Somewhere between a third and half of Americans fall into a high-risk category when it comes to the coronavirus, suggests Dr. Ashish Jha, the director of the Harvard Global Health Institute. They include people over the age of 65, nursing home residents, and people with underlying medical conditions including heart problems, chronic lung disease or a condition that attacks their immune system.

The Centers for Disease Control and Prevention website recommends that this group stay at home as much as possible and avoid close contact with others.

But it's unclear exactly how long they should be following these guidelines. So some are proceeding with maximum caution.

Clinton Mielke is considering moving to rural Oregon.

Source: Clinton Mielke

'I'm nervous'

Clinton Mielke is a data scientist at UC San Francisco who started a company to cure obesity.

Mielke feels that he could be at greater risk of complications for the virus on account of his weight. "Being 300 pounds and in that obesity category, I'm nervous."

The link between Covid-19 and obesity is not yet well understood, but some researchers and scientists say that being overweight is a risk factor. French immunology professor Jean-François Delfraissy told listeners in a radio interview, "This virus is terrible, it can hit young people, in particular obese young people. Those who are overweight really need to be careful."

Mielke, who lives in San Francisco, is considering relocating to rural Oregon to be closer to his family, but also to avoid close contact with others. He says he'll shelter in place until medications that are proven to alleviate symptoms are broadly available.

"I went through the stir-crazy period and now I'm acclimating," he said.

Mielke did say that one major downside of avoiding human contact is the lack of fresh groceries. It's been a month and a half since he's been in the presence of another person, so he's living off the remaining snacks in his pantry. "It's been nuclear bunker food," he told me.

Medical experts have tried to counsel their high-risk patients, but there are still many unknowns about the Covid-19 virus, and they're not sure what to tell them.

Dr. Nisha Basu, a primary care physician with Firefly, a virtual medical service, said she doesn't yet have a clear understanding on how long her patients should remain at home. So Basu said she's tried to help them figure out how to return to their jobs safely while avoiding exposure to the virus.

Likewise, Dr. Arturo Loaiza-Bonilla, an oncologist based in Philadelphia, is working with patients with compromised immune systems. He expects that some of them will need to come back to the hospital for tests and imaging, but he's offering virtual consults wherever possible. "We are telling them to communicate with us constantly so we can figure out the best approach," he said.

Dr. Arturo Loaiza-Bonilla with his mother Delia

Arturo Loaiza-Bonilla

The situation is also personal for Loaiza-Bonilla. His mother, who's in her 60s, is now staying next door with his young daughter. Because he's in contact with potentially infected people at the hospital, he feels more comfortable staying away from them.

He's not the only one thinking through complicated family dynamics. When one person in the household is at risk, and others are likely moving into crowded spaces such as schools and restaurants, it presents difficulties.

Jonathan Eisen, a biology professor at UC Davis, intends to keep sheltering in place until there's widespread testing and more treatment options. Eisen is one of more than a million Americans with Type 1 diabetes, which puts him at higher risk for a serious complication if he gets the virus.

As a father to teenagers, he knows his kids are getting bored and restless staying at home.

If they return to school in the fall, he's considering renting an apartment in the area or moving in with his mother and stepfather (who are also in the vulnerable, high-risk group). He recognizes that he can't expect his kids to stay six feet apart from others at all times. If he moves out for the short term, he has a bit more control over how he interacts with his family.

"I'm pretty scared," he said. "So I've been trying to prepare myself for personal social distancing that could last over a year."

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